1. Field of the Invention
This invention relates generally to a method and apparatus for recording and reproducing information signals and, more particularly, is directed to a method and apparatus for recording and reproducing audio signals and visual information signals corresponding to the audio signals.
2. Description of the Prior Art
Audio tape recording and reproducing apparatus, such as compact cassette tape recorders, generally only record and reproduce audio signals, for example, music, dialogue or the like. It is often desired, however, to record visual information on the magnetic tape along with the audio information. For example, it may be desirable to visually reproduce sheet music or the vocal arrangement for a musical arrangement or song which has been reproduced from a magnetic tape. As a further example, it may be desirable to visually reproduce teaching text while listening to audiolingual educational material reproduced in a language laboratory, or to visually reproduce a meeting memorandum corresponding to the audio reproduction of a recorded meeting. Such visual information can be reproduced on a display which forms part of, or is an accessory to, the tape recording and reproducing apparatus.
It should be appreciated that, for the sake of simplicity, the secondary visual information signal should be recorded on the magnetic tape in close proximity to the primary audio signal to which it corresponds. In one known apparatus, described in detail in U.S. Pat. No. 4,121,264, issued on Oct. 17, 1978 and having a common assignee herewith, primary information signals are recorded in first and second main or primary signal tracks and secondary signals corresponding to the primary information signals are recorded in first and second secondary tracks extending in the longitudinal direction of the tape in the center thereof between the first and second main signal tracks. In this patent, the secondary signals are control signals, such as pulses to control the operation of playback mechanisms. Due to the fact that such secondary signals contain relatively little information, they do not require as much tape width as the main signals recorded simultaneously therewith.
Generally, however, the magnetic tape housed in a compact audio cassette has a relatively narrow width. Accordingly, with cassette tape, it becomes extremely difficult to provide first and second secondary or control tracks in the center of the tape in accordance with the aforementioned patent. Further, it is to be appreciated that visual information may require more complex secondary signals than the control pulses used in U.S. Pat. No. 4,121,264, therefore requiring the use of a greater amount of tape.